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Schallintensitaetssonde. de January de Schallintensittssonde mit zwei Mikrofonkapsel und zustzlichem Abstandshalter Spacer en sound intensity probe with german labels selbst fotografiert Foto Helfer PDrelease Original upload log de Wdwdbot CommonsHelper de Schallintensitaetssonde Martinhelfer bytes no FKFS Microphones